8th Liquid Matter Conference September 6-10, 2011 Wien, Austria ...

Wed 711:10-14:00P5.147Self-aggregation and long-range ordering intwo-dimensional systems of dipolar colloidsHeiko Schmidle, 1 Carol Hall, 1 Orlin Velev, 2 and Sabine Klapp 11 Technical University Berlin, Hardenbergstr. 36, 10623, Berlin, Germany2 North Carolina State University, Raleigh, United States of AmericaWe present results of computer simulations of dipolar colloids confined to two dimensions. As onefocus we study the appearance of vapor-liquid transitions. To this end we employ Grand-canonicalMonte-Carlo simulations of Stockmayer fluids. In addition to the unperturbed systems, we alsostudy the effect of an external field parallel and perpendicular to the particles. The correspondingcritical temperatures are significantly shifted relative to the zero-field case [1]. Further, weinvestigate the self-aggregation of the system by using Discontinuous Molecular Dynamics and ashort-range representation of the dipolar colloids. We show that the system undergoes a transitionfrom an isotropic fluid phase to a polymer fluid, characterized by most particles associated intolocal clusters. Further decrease of the temperature leads to a percolated gel phase. In the highdensity region we observe freezing into a hexagonal ordered phase and a ferroelectric order atvery low temperatures.[1] H. Schmidle and S. H. L. Klapp, J. Chem. Phys. 134, 114903 (2011).147